1. Field of the Invention
The present invention relates to a seat belt retractor. In particular, the present invention relates to a seat belt retractor which may be manually actuated to block the withdrawal of belt webbing from the retractor.
2. Description of the Prior Art
Seat belt retractors which may be manually actuated to block withdrawal of belt webbing are known. Such retractors are known as having a "cinch" mechanism. Such retractors are useful for securing an article, such as a package or child seat, to a vehicle seat. Such retractors are also useful for preventing an occupant from moving relative to the seat when the vehicle is travelling on a rough surface. After the belt webbing is withdrawn from the retractor and trained about the article or occupant, the cinch mechanism associated with the retractor is manually actuated. The belt webbing cannot be withdrawn any further from the retractor and the article or occupant cannot move relative to the vehicle seat.
U.S. Pat. No. 4,327,882 discloses a vehicle sensitive seat belt retractor having a cinch mechanism which is actuated by manually depressing a button. The retractor has a pair of spools. An end portion of the button forces a pawl into engagement with ratchet wheels connected to respective spools of the retractor. The pawl blocks rotation of the spools to prevent belt webbing from being withdraw from the spools. A detent on the button maintains the button in a position holding the pawl in engagement with the ratchet wheels. When belt webbing is then wound onto one of the spools, a cam rotatable with the one spool forces a lever to move the button to a position enabling the pawl to disengage the ratchet wheels.
U.S. Pat. No. 4,427,164 discloses another vehicle sensitive seat belt retractor having a cinch mechanism which is manually actuated by depressing a button. The button is connected to a lever which pivots a locking pawl. Upon depressing the button, the lever pivots the locking pawl towards ratchet wheels connected to a spool of the retractor. When the locking pawl engages the ratchet wheels, rotation of the spool in the belt withdrawal direction is blocked and belt webbing cannot be withdrawn. However, the spool can rotate in the belt retraction direction. A feeler attached to the pawl engages the belt webbing as it winds onto the spool. When a predetermined amount of the belt webbing is wound onto the spool, the feeler moves the locking pawl out of engagement with the ratchet wheels.